Blowout preventer may have never had a chance against Gulf of Mexico oil spill

In an accident caused by a string of compounding human errors, it stood to reason that last year's Gulf of Mexico oil spill went from deadly explosion to uncontrolled environmental disaster when an automated safety device, the supposed fail-safe, also suffered multiple failures as a result of carelessness.

View full sizeOil leaking from the blowout preventer deep in Gulf waters in June.

That narrative took shape last year when investigators learned that the blowout preventer -- the four-story stack of valves, seals and slicing blades that sat a mile under the sea to shut off the well in an emergency -- had a weak battery, a hydraulic leak, mismatched plumbing and faulty wiring.

The easy explanation was that humans -- who had already cut corners and misread tests, allowing oil and natural gas to ignite the Deepwater Horizon rig in fireballs -- had dropped the ball again. They failed to maintain the BOP and report the litany of problems to authorities. And at the critical moment just before the blowout, they didn't recognize the need to close in the well.

But the story that emerged last week with the release of a technical forensic report is a little more complicated, and it has potentially troubling implications for the future of deepwater oil drilling. In short, the blowout preventer -- like others in the deepwater -- simply might not have been up to the task.

Marine Board hearings begin Monday in Metairie

When the authors of the report from Norway-based Det Norske Veritas come to the Marine Board of Investigation hearings starting Monday in Metairie, they, along with specialists from rig owner Transocean and BOP manufacturer Cameron International, are sure to face tough questions about whether any blowout preventer could have overcome the forces at BP's Macondo well.

Yes, Transocean's crew members missed warnings signs. Yes, key systems in the Deepwater Horizon's BOP were in disrepair, which probably kept it from shutting in the spewing well and disconnecting from the burning rig right after the explosions on April 20, 2010. But within days, scientists in Houston armed with remote-control submarines hovering 50 miles off the coast of Venice and a mile below the listing rig were able to activate critical BOP functions. Their intervention should have limited the spill to a relative puddle.

Instead, the spill became the worst in U.S. history because, as Transocean said after Det Norske Veritas' autopsy was released, "conditions ... exceeded the scope of BOP's design parameters."

In other words, the report suggests that the Deepwater Horizon's blowout preventer -- and, by inference, all blowout preventers being used by all rigs drilling deep, dangerous wells -- never had a chance.

Even before the explosions that killed 11 men on the rig, something happened inside the BOP that was at once unexpected and incredibly simple. The small group of 10 crew members who had an inkling of the danger bubbling up from below, 10 of the 11 who died, successfully closed two sets of the BOP's rubber seals around a drill pipe that was 5.5 inches in diameter. That created pivot points on the pipe. With the seals locking the metal pipe in place, intense pressure mounting from miles below the sea floor caused it to bow in the middle of the BOP, the report said.

The pipe was thus knocked off center in the place where it could least afford to be. Blind shear rams, two hunks of metal with blades and rubber seals, were supposed to fire into the BOP's central chamber from either side, grab the drill pipe, slice across it and permanently close off the path of oil, gas and sediment.

With the pipe off-center, the rams couldn't get a good hold of it, didn't get a clear cut and fell 2 inches shy of sealing properly.

The rest is an object lesson in the power of high-pressure oil and gas finds. The hydrocarbons eroded the metal rams like a thin stream of scalding hot water through the center of a chunk of ice. Seven days later, when the engineers got another set of slicers to work a few feet farther down, the stream got larger, battering the whole underside of the rams, eroding them further and creating even more pathways to the surface.

Critical challenges ahead

The BOP autopsy points out some critical challenges for the industry as it looks to drill increasingly challenging wells, said Bob Bea, a University of California at Berkeley professor of civil and environmental engineering, former drilling rig-hand and risk management expert. The problem is that BOPs on most deepwater drilling rigs are mostly about a decade old and aren't designed to meet those challenges, he said.

"The early 2000s generation of BOPs do not have the reliability needed to conduct these operations -- reliability that is at least two orders of magnitude (100 times) more reliable than the conventional BOPs have demonstrated," Bea said. "The likelihoods of BOP failure were substantially higher than generally appreciated."

A buckling drill pipe, for instance, was never anticipated. But studies commissioned by government regulators, particularly a West Engineering report from 2004, show other potential problems. The West report found that heavier, more elastic pipes are being used in deeper drilling and can be difficult or impossible to shear, even when held in tension. It also showed that tests often don't properly account for the high pressures in the deep sea, and noted that industry data about actual deployments of shear rams was hard to come by.

The Bureau of Ocean Energy Management, Regulation and Enforcement says new safety requirements for BOPs, implemented since last year's disaster, provide a new level of oversight by the government. But the key will be how the industry responds with new standards.

Keeping the regulators happy

When it comes to spill response, oil and gas companies have acted quickly to appease government regulators. Two groups developed new devices for capping a well and collecting the discharge, while also establishing contracts to make sure the necessary equipment gets anywhere in the Gulf in a matter of days.

The industry's lobbying and standards-setting arm, the American Petroleum Institute, is working for better readiness with BOPs, too. API recently created a new Offshore Safety Institute to address problems brought to the fore by the BP incident. API is in the process of re-writing its Recommended Practice No. 53, covering BOP testing and components. Erik Milito, API's director of exploration and production, said more than 50 experts will provide a final document for public review and a vote by members "in the next few months."

"The requirements will ultimately address preventing this from happening at all and making sure that BOPs work as expected," Milito said. "The government is involved in the process, and overall we've already seen significant enhancement to allow the industry to go forward with a lot more confidence."

But with federal regulators beginning to hand out deepwater drilling permits again, not everyone is so sure the last line of defense is really ready.

"Now we know there could also be systemic design issues with blowout preventers that could cause them to be ineffective, even when deployed as intended," Rep. Ed Markey, D-Mass., said when the Det Norske Veritas report first came out. "We need a full review of every single blowout preventer used in United States waters, and revisit the designs of these supposed machines of last resort."